666536635667 has 12 divisors (see below), whose sum is σ = 788500623960. Its totient is φ = 561633772896.

The previous prime is 666536635649. The next prime is 666536635717. The reversal of 666536635667 is 766536635666.

It is not a de Polignac number, because 666536635667 - 2⁶ = 666536635603 is a prime.

It is a Smith number, since the sum of its digits (65) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (666536635067) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 115274978 + ... + 115280759.

It is an arithmetic number, because the mean of its divisors is an integer number (65708385330).

Almost surely, 2^666536635667 is an apocalyptic number.

666536635667 is a deficient number, since it is larger than the sum of its proper divisors (121963988293).

666536635667 is a wasteful number, since it uses less digits than its factorization.

666536635667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230555810 (or 230555803 counting only the distinct ones).

The product of its digits is 440899200, while the sum is 65.

Subtracting 666536635667 from its reverse (766536635666), we obtain a palindrome (99999999999).

The spelling of 666536635667 in words is "six hundred sixty-six billion, five hundred thirty-six million, six hundred thirty-five thousand, six hundred sixty-seven".